[Brian Duff]

Umm, I think the upper should be as large as the lowers. (Load supposed to be 32.5% on each of the 2 lowers per side, 45% on the upper - in theory, see Brion Toss 'The Riggers Apprentice' or any yacht design book). We re-rig Valiant 40's with a forestay, backtsay, uppers and lowers of 3/8" 1b19 cable and the inner forestay and deck intermediates of 5/16" 1by19 cable. All the pins on the mast and chainplates are usually 5/8", except the inner forestay stuff is sometimes 1/2" , on those boats.

On that boat, or anyboat with bonded chainplates (yuck!) and or internal chainplates, be sure to remove and inspect the chainplates as part of the re-rigging. It doesn't matter if there are no evedince of leaks, check them anyway, why spend $6500 on rigging (just materials cost) if the chainplates might break ?
Be sure someone that knows what they are looking at inspects the chainplates. We just re rigged a V40 and the owner removed chainplates himself (to save $$), took them to a local metalshop to be polished/inspected. Well, we got back the 10 chainplates, of which 3 were OK to use ! All the others had cracks in them (I recall it was a 1979 boat). I know the starboard chainplates for the upper and fwd lower are hard to get out but do it.
Also, the tang bolts, compression tubes and tangs should be checked. These rigs have aluminium compression tubes that have often corroded away or been cut by the wire halyards they came with.

Nice boat really (it seems from working on them) , I hope to get some ocean sailing on one some day...